Sphere-smoothing method and apparatus



' Dec. 22, 1942. w. E. HUMPHREY SPHERE-SMOOTHING METHOD AND APPARATUSFiled Jan. 8, 1942 lNVE-NTOR O ,WW

Patented Dec. 22, 1942 SPHERE- SlvIOOTHING METHOD APPARATUS AND WalterE. Humphrey, Jeannette, Pa.

Application January 8, 1942, Serial No. 426,021

3 Claims.

This invention relates to the smoothing of the surfaces of sphericalarticles, and finds practical application in the smoothing and pressingof the felt covers upon tennis balls, and in the closing of the seams atthe meeting edges of the applied covers, before the covered balls arevulcanized. An ultimate vulcanizing step is taken, to accomplish thevulcanization particularly of the intercalated fihn of rubber cement bywhich the cover is caused initially to adhere to the rubber shell, andto integrate the whole. Invention is found both in method and in theapparatus for performing the method of smoothing and pressmg.

In the accompanying drawing, Fig. I is a view, partly in side elevationand partly in vertical section, of apparatus built in embodiment of theinvention. Fig. II is a view of the apparatus in plan from above, theupper of two companion plates having (for purposes of illustration) beenremoved. In Fig. II the plane of section of Fig. I is indicated by theline 1-1. Fig. III is a View in vertical and transverse section, on theplane indicated at III-III, Fig. I.. Fig. IV is a diagrammatic view,illustrating the progressive operation of the apparatus upon a ball.Fig. V is a fragmentary View to larger scale showing in perspective andin inverted position a portion of the structure.

Over the surface of a smooth and rigid table I, advantageously formed ofhard maple plank and arranged in horizontal plane, a web 3 of cottonbelting advances. The web is advantageously an endless belt, organizedas shownin Fig. I. It is mounted upon two drums 4 and 5 that are placedbeyond the opposite ends of the table. The belt is driven from a sourceof power I through a shaft 6, upon which one of the drums (4) ismounted.

Above and suitably spaced from the web-faced table-top I are set blocks2 in succession longitudinally of the table-top. These blocks areconveniently formed as downward extending eminences upon the nether faceof a plate 20. The plate with its eminences is conveniently formed ofhard maple and is accurately spaced from and rigidly placed in itsrelation to the table-top l.

Comparing Fig. V with Fig. I, it will be seen that each block 2 presentsa horizontal lowermost surface 2! that extends in parallelism to thetable-top l, and an inclined surface 22 that slopes from higher leveland meets the horizontal surface 2!. The blocks 2 conveniently extendlaterally throughout the width of the table-top, and they are soarranged that a ball resting upon the belt 3 is by the advance of thebelt rolled under the inclined surfaces 22 and under the horizontalsurfaces 2|. As shown in Fig. I, nine blocks 2 are built into thisparticular organization; and, in sequence from right to left, theinterval at which the lower faces 2! of the first five of these blocksare spaced from the table-top I is greater than that at which thesucceeding four are spaced.

Above the web-faced table-top are arranged two series of vertical andobliquely extending abutments, 8, 8, etc. and 9, 9, etc, the series 9,9, etc. succeeding the series 8, 8, etc. The two series extend from thetwo sides of the webfaced table-top; and within each series thesuccessive abutments extend to greater andgreater distance from theside, across the width of the web. There remains, however, freepassageway for a web-borne ball in direct course, beyond the end of thelast abutment of each series. The abutments 8, 8, etc. and 9, 9, etc.are in the assembly arranged in the intervals in the succession ofblocks 2, 2, etc. It is convenient to form the abutments as faces ofplates ii and II that project from side walls l2, upon which side wallsthe plate 20 finds rigid support.

At the right-hand end of the apparatus, as

seen in Fig. I, a funnel-shaped opening I? is formed through plate 26for the introduction one by one of the balls to be rolled. I

In operation an in-fed ball descends and rests upon the travelling web3. The right-to-left advance of the web carries the ball beneath thesuccessive blocks 2 and to bearing upon the successive abutments 3 and9. In the intervals between the blocks 2, the space interval between theweb-faced table-top and the block 2 is greater than the diameter of theweb-borne ball. The blocks 2, howevenare so spaced from the tabletopthat the advancing ball, engaged by them, is rolled beneath them, andunder pressure that increases as the ball rolls over the inclined faces22 and at a continuing maximum pressure as the ball rolls over thehorizontal faces 2 l The length of the blocks 2 in the direction of balltravel is advantageously such that in passing beneath each block theball is rolled through one complete rotation; and, since the blocks areset square across the line of advance, the rolling is centered on agreat circle of the ball. The length of the surface 2| in the directionof rolling is equal to half the circumference of the ball; and the ball,compressed between the surface 2! above and the Web-faced table-topbelow, is pressed at maxivance of the web is to cause the ball to rollalong the face of that abutment, and in so doing to shift in itsposition laterally upon the face of the web 3. The advancing web 3 thusrolls the ball across the face of and beyond the end of the abutment,and when it has rolled the ball beyond the end of the abutment the webin its further advance brings it beneath the next succeeding block 2,and there it is again rolled and compressed, and this second rolling isupon another great circle than that of the preceding rolling.

Since the ball is rolled under pressure between the nether surface ofthe block, and the Web-faced upper surface of the table, there will bein each step an area of compression, a path of surfaceupon-surfacecontact, that extends in a belt around the ball. In Fig. IV such beltsof compression are indicated by shading. Beneath each block 2 one suchbelt of compression is developed. The abutments 8, 8-9, 9 etc. are ofsuch extent that the successive belts of compression are developed asindicated in Fig. IV, overlapping at polar points and side-by-side atthe equator, so that, on passing beneath a sufdcient number of blocks,the ball is at every point in its surface compressed between the opposedcompression members.

Manifestly, the greater the extension of the blocks 2 from the netherface of the plate 29 and the narrower the interval between the surface2! of the block and the web-faced tabletop, the broader will be the beltof compression. And in the drawing I have, by way of example, indicatedthat beneath the five blocks to the right (Fig. I) belts of compressionare developed of a breadth of 36 or more, measured on a great circle ofthe ball; and thus beneath thefive blocks the entire surface of the ballis compressed.

I find it desirable to make this operation of rolling and compressingthe applied cover a twostep operation. (It might, manifestly, be made athree-step operation, or more; but I find two steps sufficient.) I rolland compress in a first step, with the apparatus and by the proceduredescribed, under relatively light pressure; then,

having secured a more complete adhesion of the cover to the ball, I rolla second time under greater pressure, and at the pressure necessary toafford a completely satisfactory'article. It is for such second rollingunder increased pressure that the second set of blocks 2 is provided.These are the blocks to the left, Fig. I; and, since they are of greaterextension from plate 20, and the belt of compression developed by themis broader, a smaller number (four as against five) sufiices to effectcompression over all the surface of the .ball. The abutments 9, 9 etc.of the second set are correspondingly adapted in their extent to affordthe proper equatorial spacing of the rolled belts. The reversal in thearrangement of the two plates l9 and II with their abutment surfaces isa matter of convenience merely. By such reversal of arrangement the ballis shifted upon the table, first from right to left (Fig. III), and then(as will be manifest) from left to right; and so table and belt are keptnarrow and structure simple.

Referring to Figs. I and II, a ball introduced at I3 is borne by the Web3 from right to left. When in position a it is in course of rollingbeneath the first of the blocks 2; in position b it has just beenshifted by the conjoint action of the web 3 and the first of theabutments 8 to position for rolling beneath the second of the blocks; inposition 0 it is in course of rolling beneath the second of the blocks2, and so on. In position 11 it is in course of rolling beneath thefifth of the blocks 2 (the last of the blocks of low downward extensionfrom plate 20). In position 'c it has been shifted to position to berolled beneath the first of the blocks of greater extension from plate20; in position 1 it is in course of rolling beneath such last-namedblock; and so on, until at length, passin'gfrom beneath the last of theblocks 2 the ball emerges, as indicated at g, and escapes as indicatedath, Fig. I.

I claim as my invention:

L'The method herein described of smoothing and increasing adherence of anewly applied cover upon a compressible playing ball which consists inrolling the ball upon a pluralityof great circles' between compressionsurfaces of Wide spacing and thereafter rolling the ball upon aplurality of great circles between compression surfaces of narrowspacing.

2.'Apparatus for smoothing the surface of a compressible sphericalarticle which consists of a rigid table, a flexible web movable inright-line course upon the table, a plurality of compression blocksarranged at an interval above the table and spaced apart inthe'direction of web travel and adapted to effect the rolling over theirnether faces of a spherical article of a diametergreater than theinterval at which they are remote from the table when impelled by themoving web, and an abutment arranged in the spacebetween two of the saidblocks and having a surface obliquely disposed to the line of directionof web travel and adapted to effect lateral movement upon'the we-bof aspherical articlein response to'web travel.

3. Apparatus for smoothing the surface of a compressible sphericalarticle which consists of a rigid table, a flexible web movable inright-line course upon the table, two sets of'compression blocksarranged at different intervals above'the table, spaced apart in thedirection of web travel, and the blocks of each set also spaced apart inthe direction of web travel, the intervals at which the two sets ofblocks stand remote from the table being (in the direction of webtravel) first wide and then narrow, and abutments arranged in the spacebetween successive blocks and adapted to effect lateral shift of anarticle borne by the moving web.

' WALTER E. HUMPHREY.

